1. Field of the Invention
The present invention relates to a technique that is effective when it is applied to an imaging device for image-capturing an image (particularly, an image in which a person's face is image-captured), an information processing device or an output device that handles an image, a software or the like.
2. Description of the Related Art
Conventionally, a red-eye phenomenon wherein a pupil or whole pupil of the image-captured person is image-captured to be red becomes a problem, regardless of a digital camera or silver-halide camera. As a similar problem, there is gold-eye phenomenon in which a pupil or whole pupil of a person is image-captured to be gold. The red-eye or gold-eye phenomenon described above (hereinafter, the explanation is made by taking the red-eye phenomenon as an example) is a phenomenon caused such that flash light incident on a bulb of an eye from a pupil region is reflected on the retina. Since the distance between the optical axis of a camera and a flash becomes close to each other recently due to the miniaturization of a camera, the rate of occurrence of the red-eye phenomenon increases, which becomes a problem in particular.
A red-eye preventing flash has been proposed as a technique for preventing and reducing the above-mentioned red-eye phenomenon. This is a technique wherein a flash is lightly emitted immediately before the image-capture, and then, the flash is again emitted. According to this technique, the pupil of the image-captured person is contracted by the first emission, so that the occurrence of the red-eye phenomenon by the flash after that can be prevented and reduced.
However, when the red eye phenomenon occurs, the red eye is required to be image-corrected, so long as the image cannot be retaken. As an image-correction technique as described above, there has conventionally been proposed a method wherein a pixel having the red-eye phenomenon is designated and the color of this pixel is changed to correct the image.
Further, in the case where a color of a pixel having the red-eye phenomenon occurring is changed, it is required that the pupil color after the change is determined. As a technique for determining the pupil color, there has conventionally been proposed a technique wherein a user selects a pupil color recorded in advance every race for changing the color of the pixel of the pupil by using this selected color. Moreover, as a similar technique, there has been proposed a method wherein a natural-looking pupil color is selected among a plurality of patterns such as “a pattern turned to look like an European” or “a pattern of Orientals”, to thereby make a change by using this color.
However, the image of the pupil having the red-eye phenomenon already occurring loses the original color of the pupil. Therefore, it is difficult to estimate the original color of the pupil from the image of the pupil having the red-eye phenomenon. If the original color of the pupil cannot be estimated, it is naturally difficult to produce a natural image even if the correction is intended to be executed by using a conventional technique.
Further, even if the above-mentioned techniques are applied, a user is required to estimate the race of the subject by a visual observation. In general, there are not so many users having knowledge about the race, so that estimating the pupil color based upon the race is a difficult and troublesome process for the user.
Additionally, it is considered that, as a method for correcting the color of the pupil, a reddish section is simply removed from the color of the pupil having the red-eye phenomenon, not replacing the color of the pupil by estimating the original color of the pupil. However, there is a problem upon performing such a correcting method. A person's sight has a feature of judging colorfulness by a color contrast. Therefore, in the case where a subject is a ruddy-cheeked person or a subject is photographed under a red illumination, there is a possibility that an unnatural image is produced on the contrary only by performing the correction for simply removing the reddish section from the color of the pupil.